Electromagnetic-wave-generating system



M. LATOUR Oct. 12 1926. 1 02 4 9 ELECTROMAGNETIC WAVE GENERATING SYSTEM Original Filed July 15. 1920 INVENTOR W nds Z a, taur ATTORNEYS Patented Oct. 12, 1926.

UNITED STATES PATENT OFFICE.

MARIUS LATOUR, OF PARIS, FRANCE, ASSIGNOR TO LATOUR CORPORATION, OF JER- SEY CITY, NEW JERSEY, A CORPORATION OF DELAWARE.

ELIEGTROMAGNETIC-WAVE-GENERATING SYSTEM.

Original application filed .1u1y15, 1920, Serial No. 396,499, and in France February this application filed October 30, 1923. Serial No. 671,640.

15, 1916. Divided and.

(GRANTED UNDER THE PROVISIONS THE ACT OF MARGH 3, 1921, 41. STAT. L, 1313.)

v The present, invention relatesto an improved generating system for tl1e electr0- magnetic wave transmission of speech using thermionic valves or elements, and relates u h u Figure 1 shows diagrammatically one formof arrangement for feeding. an antenna;

Figure 2 is a diagram showing a modified form of construction.

The thermionic valve generator or element 1 contains as is usual an anode 2, a grid 3, and a filament 4; heated from a battery 5. The aerial 6 is connected to the ground 7 through a self-inductance coil 8. A second coil 16 is reactively coupled to this coil 8 and is connected between the grid and the filament to serve as a means for exciting the thermionic generator. Finally a source of electromotive force is applied across the anode and filament of the thermionic element.

According to the present invention, there is arranged in series with the coi-l'16 between the grid and the filament, an impedance formed by an inductance 10 and a capacity 11 connected in parallel and substantially tuned to the wave-length of the thermionic generator.

This impedance can easily be made very large and of the order of magnitude of the resistance of the thermionic element between grid and filament.

The microphone 12 is placed, for instance, in series with the inductance.- Under this condition. the impedance is proportional to the microphone resistance and the variations of microphone resistance give corresponding variations in the impedance. It may be said that the arrangement functions as if one had substituted for a microphone of low resistance a very high resistance microphone (of the order of magnitude of the resistance of the thermionic element between grid and filament) and is more suitable for controlling the grid-filament current of the oscillating thermionic element.

. In the arrangement described above, it is obvious that the microphone 12 can be placed in series with the capacity 11 to obtain the same results.

Figure 2 shows a second method of carrying out the invention. It will be seen that the usual arrangement of thermionic generator is to be found which is lettered with similar reference letters to the arrangement shown in Figure 1.

The arrangement of microphone is differ ent. A second thermionic element 13 has its anode-filament circuit connected in series in the grid-filament circuit of the transmitting generating thermionic element 1. This second thermionic element consequently receives across its anode and filament the voltage existing across the grid and filament of the thermionic element 1. The microphone 12 is placed in series with a battery 14: and the primary winding of a transformer '15, the secondary of which is connected between the grid and filament of the thermionic generator 13.

It will be seen that in this arrangement the variations of microphone current will in fluence the maintaining of oscillations in the sending thermionic valve generator 1.

Having described my invention, what I claim is:

1. A radio signaling system comprising means for radiating oscillations, a threeelectrodethermionic oscillation generator associated with said radiating means, and means for influencing the output energy of said oscillation generator, said means including a three-electrode thermionic tube in series with the grid-filament circuit of said oscillator.

2. In a signaling system,. a transmission circuit, a three electrode thermionic oscillation generator coupled to said transmission circuit, and means for influencing the output energy of'said oscillation generator, said, means including a modulating three electrode thermionic tube in series with the grid-filament circuit of said oscillation generator.

3. In a signaling system, an oscillation generator comprising'a thermionic tube provided with an input circuit and an output circuit, modulating means for controlling said oscillation generator including a thermionic tube having a filament, a control electrode, and a plate, the input circuitof saidgenerator serially including the plate and filament of said second thermionic tube, and

. signal-controlledmeans for governing said control electrode.

4. In a signaling system, an oscillation generator comprising a thermionic device provided With input and output circuits, a

'modulating thermionic tube having a filasignal-controlled device .for. introducing energy into said last mentioned circuit.

5. In a s gnalingsystem, an osc1llation generator comprlsing a thermionic device provided with reactively coupled input and output circuits, a second thermionic device including an input electrode and an output electrode, said output electrode being serially included in said input circuit and signalcontrolled: means associated with said input electrode for governing said input circuit.

6. In asignaling system, a transmission circuit, a three-electrode discharge device having an anode-cathode circuit coupled to said transmission circuit, a grid-cathode circuit for said discharge device. a three-electrode modulating device having its output circuit serially included in said grid-cathode circuit, an input circuit for said modulating device, and signal-controlled means for variably controlling said input circuit.

MAR'IUS LATOUR. 

